Air compressor



Jan. 10,1928.

1,55,61s A. G. LARSON AIR COMPRESSOR Filed Dec. 15, 1925 INVENTOR. WWXa-Mm 3 wK 21M1r 2 ATTOR EYS.

Patented Jan. 10, 1928.

UNITED STATES PATENT OFFICE.

ALBERT G. LARSON, OF PIEDMONT, CALIFORNIA.

AIR COMPRESSOR.

Application filed December 15, 1925. Serial No. 75,496.

haust valves in the head directly over thecylinder end. This practice isobjectionable for necessarily limits the size of these valves,

making them inefficient in operation. Also, it is. particularlyobjectionable to mount the intake valve in this manner, since the valvestem occasionally breaks or the threads thereon become worn and permitthe valve to drop directly into the cylinder, thus causing considerabledamage. It is an object of my invention to provide a compressor in whichonly the exhaust valve is mounted in. the head over the cylinder, theintake valve being mounted in the body of the compressor. I am awarethat ball valves have been heretofore mounted in a similar manner, butsuch construction is inefficient and objectionable for reasons.hereinafter stated.

My improved compressor uses the well known pocket or plunger valve whichis most efficient in machines of this type. I mount the exhaust valve inthe head of the compressor and the intake valves in the body of thecompressor between two adjacent cylinders thereof, a common intake portpreferably being provided for both in take valves and a communicationbeing provided from each intake valve to its cylinder by grooving theadjacent faces of the body and head of the compressor.

It is another object of my invention to provide an improved compressorof this type.

A further object of my invention resides in the provision of an improvedarrangement of cooling fans for the compressor. In accordance with thisfeature of the invention, I mount a fan shaft in a bearing extendingtransversely of the compressor between two adjacent cylinders thereofand preferably mount two fans respectively on the ends of this shaft atopposite sides of the compressor.

In the accompanying drawing I have illustrated certain specificembodiments of my invention, but it will be understood that theinvention can be otherwise embodied and that the drawing is not to beconstrued various reasons. -Suchconstruction as defining or limiting thescope of the invention, the claims appended to this specification beingrehed upon for that purpose.

Referring to the figures of the drawing Flgure 1 is a longitudinalsectional View through my compressor taken on line II- of Fig. 4.

Figure 2 is a transverse sectional view thereof taken on line IIII ofFig. 4. f

F igure3 is partial plan view.

Figure 4 is a plan view with the head removed.

Inthe drawing, 1 indicates the crank case 2 the body, and 3 theremovable head of my compressor. Pistons 4.- operating in cylinders 5are connected to the crank shaft 6 by pitmans 7.

An opening 8 is provided through the head 3 into each cylinder. Thebottom of each such opening is formed into a valve seat for receiving avalve 9 having a stem 10 guided within a closure plug 11 threaded intothe opening. A spring 12 is provided for normally holding each valve inits closed position. Outlet ports 18. are provided from. the chambers 8.

The inlet valves 14- are provided in the body 2 between the cylinders.Each of these valves rests on a seat over an opening in communicationwith a common intake port 15. The'stems 16 of these valves are guided inholes in the head 3. Springs 17 normally hold the valves closed. Asillustrated, both cooperating faces of the body and head are grooved toprovide ports 18 leading from the intake valves to the cylinders. Theair or gas to be compressed is brought in by a pipe 19.

Directly beneath the port 14 I provide a shaft bearing through the body1 between the two adjacent cylinders and I mount a fan shaft 20 in thisbearing. The shaft may be driven by a belt 21 running over a pulley 22.The fans 23 on the opposite ends of the shaft at opposite sides of thecompressor are adapted to very efliciently cool the compressor uponrotation of the shaft.

It is believed that the advantages of my invention will be obvious. Theseveral cooperating parts of the compressor are extremely simple and somounted as to be most readily accessible. The exhaust valves 9 arereadily accessible for repairing or grinding the valve seats merely byremoving the plugs 11. The intake valves 14 are readily accessible byremoving the head 3.

The form of valves used may be the tapered valve shown in the drawing orflat disk valves. Such type of valve permits 0'? a very large valveopening beneath the valve seat without adding greatly to the weight ofthe valve and without requiring additional valve space above the valveseat. This is not true of ball valves, since increasing the diameter ofthe ball of such a valve greatly increases the weight and height of theball. It will be noted that the valve openings at the ends of thecylinders are relatively large, being nearly the size of the cylinders.This construction adds greatly to the efficiency ot the compressor andcannot be attained where both the inlet and outlet valves are located atthe end of the cylinder. Furthermore, there is no danger of the valvedropping down into the cylinder as is the case when the intake valve ismounted in the head as heretofore described.

The location and arrangement of the intake valves 14 provide not only anefiicient construction, but also a construction very easy and cheap tomanufacture. A single intake port 15 is provided for both valves and thesize oi the valves can be as large as desired. The ports 18 are formedmerely by grooving the cooperating surfaces of the head and body and canbe of any size desired.

My invention is believed to overcome the objections heretofore existingin air compressors and to provide a more simple, cheap and efficientcompressor than has heretofore been known.

Having thus described my invention, what I claim is:

1. An air compressor comprising the combination of a body having a pairof cylinders therein, a piston in each cylinder, a remov able headclosing the outer ends of the cylinders, a pair of outlet valves inthehead respectively over the ends of the cylinders, said cylinder bodybeing provided with two inlet valve chambers and seats, and being alsoprovided with a bore forming intakes to the chambers, a pair of inletvalves resting on the seats and having steinsextending into and guidedby the head, aspring around each stem between each valve and head, saidcylinder body being also provided with grooves between the body and headproviding communication from the intake valves to the cylinders.

2. An air compressor comprising the combination of a body having a pairof cylinders formed therein, a piston in each cylinder, a removable headclosing the outer ends of the cylinders, a pair of outlet valves in thehead respectively over the ends of the cylinders, a stem on each valveprojecting into the head and guided thereby, a spring surrounding eachstem and interposed between the head and the valves, said cylinder bodyhaving formed therein two inlet valve chambers and seats in the bodybetween the cylinders, said cylinder body having also formed therein abore forming intakes to the chambers, and a pair of inlet valvesresting.

on the valve seats, said cylinder body having formed therein groovesbetween the body and the head providing communication from the intakevalves to the cylinders.

ALBERT G. LARSON.

